There has been considerable prior art effort to find desirable ways of inserting, occluding in place and removing pivot rods which connect modular links together into a belt. To successfully achieve this, the method of inserting and removing the pivot rods should be conveniently done in the field for repairs, etc. as well as in the factory when making belts. The occlusion must be such that it conforms to different belt working conditions such as loading, tension, slack and path curvature. Also it must be such that there is no chance during a normal range of operating conditions that a journalled pivot rod can escape or move axially away from a specified pivoting position.
There have been problems introduced in the prior art methods of inserting and removing pivot rods because critical alignments of modules and pivot rods are required under special conditions that make it awkward and tedious to assemble belts or to replace defective pivot rods or modular links in the field. Where flexing of occlusion members integrally appended to the belt modules is permitted, there may be failure because of frequent or inadvertent flexing.
Some pivot rod occlusion systems are dependent upon headed or deformed pivot rods, which are expensive and difficult to stock and change in the field. Also detenting arrangements requiring the pivot rod to move are subject to wear and deterioration in use. Any laterally elongated journalling apertures permitting movements of pivot rods along the length of the belt can produce problems of changing belt length and wear under conditions of load and slack.
Representative prior art is J. M. Lapeyre, U.S. Pat. No. 5,058,732, Oct. 22, 1991 and M. K. Tan U.S. Pat. No. 5,105,938, Apr. 21, 1992.
It is therefore an object of the present invention to provide an improved occlusion system and accompanying modules that overcome prior art problems and facilitate the use of cylindrical non-headed pivot rods.